This application claims priority to an application entitled xe2x80x9cMethod of Automatically Reconnecting Dropped Call in Mobile Communication Systemxe2x80x9d filed in the Korean Industrial Property Office on Dec. 3, 1998 and assigned Serial No. 98-52759, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to the field of wireless communications, and in particular, to a method of reconnecting a dropped call in a mobile communication system.
2. Description of the Related Art
In a public land mobile network (PLMN), a connection is made between a base station (BS) and a mobile station (MS) in a radio environment. In some cases, call service cannot be provided in shadow areas due to physical characteristics of the radio environment which adversely affect signal propagation. In the case where a terminal subscriber roams on foot or is moving in a vehicle, a call can be temporarily dropped. In accordance with conventional technology, if a call drop lasts for a predetermined time period, it is determined that call service cannot be provided and the call is released. In IS-95, the predetermined time is approximately 5 seconds (i.e., equal to one frame duration 20 msxc3x97270). Upon this unintended call release, the calling party must attempt to call the called party again.
To overcome the aforestated problem of call drops, several approaches have been suggested in the prior art including:
(1) U.S. Pat. No. 5,546,382: reconnection of a circuit to continuously provide a data communication service upon generation of a transmission failure;
(2) U.S. Pat. No. 5,239,571: reconnection of an abnormally terminated communication line by adding a separate device to a terminal or modifying the terminal. That is, with the aid of a RAM in the terminal for storing information on call origination and call termination, a call is automatically set up in the case of an abnormal disconnection of a call; and
(3) U.S. Pat. No. 5,566,236: reconnection of a disconnected telephone communication by use of a nearby telecommunication system (e.g., PBX: Private Branch Exchange, and Centrex: Centralized PBX Service) whereby the concept of an intelligent network is introduced.
An object of the present invention is to provide a method of automatically reconnecting a dropped call during call setup by paging in a mobile communication system.
Another object of the present invention is to provide a method of automatically reconnecting a call dropped during call service by paging in a mobile communication system.
Briefly, these and other objects are accomplished by a method of automatically reconnecting a communication link terminated by a service impediment during service between a mobile terminal of a first subscriber and a terminal of a second subscriber with the first subscriber communicating through one of a plurality of base stations (BSs) connected to the mobile terminal and at least one of a plurality of mobile switching centers (MSCs) connected to the BS in a mobile communication system having the plurality of BSs and the plurality of MSCs. In accordance with the method, when the service impediment lasts for at least a first predetermined time period, the serving BS transmits service impediment detection information to the MSC connected to the serving BS. Then, at least one of the BSs which receive a reconnection paging request from the MSC attempts a reconnection paging. The terminated service is reinitiated between the mobile terminal of the first subscriber and the terminal of the second subscriber through a BS which receives a response for the reconnection paging from the mobile terminal of the first subscriber and one of the plurality of MSCs connected to the BS, when the mobile terminal of the first subscriber responds to the reconnection paging.